Modified Trabeculectomy After Failure of Combined Phaco With GATT

Since the advent of GATT or phacogoinotomy as MIGS, ab-externo canaloplasty and NPDS have become essentially obsolete. The ab-interno techniques to vasodilate Schlemm's canal and goniotomy have largely replaced ab-externo canaloplasty.

. Although the GATT procedure and phacogoinotomy is, minimally invasive methods, yet it needs normal functional collector orifice and not respect physiological function of trabecular meshwork,8 as these procedures depend mainly on incision and damage of trabecular meshwork360 degree in GATT 120 in goniotomy, the main disadvantage of these procedures it is not so suitable for narrow angle glaucoma and have many complications as post operative hyphemia with IOP spike, PAS, corneal injury and create cyclodialysis Moreover trabecular meshwork and Schlemm's canal are vital structures can repair themselves through limbal stem cells or even peripheral iris can cover the incision as the part of repair. The main disadvantage is that the trabeculectomy should not be relied upon when the target IOP is in the low teens. Also, these procedures are expensive and need a long learning curve, hyphemia can prevent completion of the operation.